<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>BigInt</title>
</head>
<body>
  <script>
    // 大整型
    let n = 521n
    console.log(n, typeof(n))   // 521n 'bigint'

    //函数
    let m = 123
    console.log(BigInt(m))   // 123n
    // console.log(BigInt(1.2))  // 会报错，不能跟小数

    //大数值运算
    let max = Number.MAX_SAFE_INTEGER
    console.log(max)   // 9007199254740991
    console.log(max + 1)   // 9007199254740992
    console.log(max + 2)   // 9007199254740992

    console.log(BigInt(max))   // 9007199254740991n
    console.log(BigInt(max) + BigInt(1))   // 9007199254740992n
    console.log(BigInt(max) + BigInt(2))   // 9007199254740993n
  </script>
</body>
</html>